AS WITH spoken languages, there is no “universal” sign language. Different countries have their own versions, which are related to local cultural and religious backgrounds. For example, American Sign ...

Sign languages can help reveal hidden aspects of the logical structure of spoken language, but they also highlight its limitations because speech lacks the rich iconic resources that sign language ...

Written language is an evolutionarily recent human invention; consequently, its neural substrates cannot be determined by the genetic code. How, then, does the brain incorporate skills of this type?